Dear R People: Suppose I have the following: x <- 1:4 And I want to create the following matrix: 1 2 3 4 2 1 2 3 3 2 1 2 4 3 2 1 Is there a function in place for this, please? I looked at symMatrix in micEcon and some of the items in Matrix, but they didn't quite do it. I can put together something quickly, of course, but it seems likely that this would exist. Thanks, Erin -- Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown mailto: erinm.hodgess at gmail.com
> toeplitz(1:4)[,1] [,2] [,3] [,4] [1,] 1 2 3 4 [2,] 2 1 2 3 [3,] 3 2 1 2 [4,] 4 3 2 1 Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf > Of Erin Hodgess > Sent: Thursday, September 06, 2012 6:11 PM > To: R help > Subject: [R] creating a symmetric matrix > > Dear R People: > > Suppose I have the following: > > x <- 1:4 > > And I want to create the following matrix: > > 1 2 3 4 > 2 1 2 3 > 3 2 1 2 > 4 3 2 1 > > Is there a function in place for this, please? I looked at symMatrix > in micEcon and some of the items in Matrix, but they didn't quite do > it. > > I can put together something quickly, of course, but it seems likely > that this would exist. > > Thanks, > Erin > > > -- > Erin Hodgess > Associate Professor > Department of Computer and Mathematical Sciences > University of Houston - Downtown > mailto: erinm.hodgess at gmail.com > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
You asked for existing functions, but I was more intrigued by trying to
create one:
symmat <- function(n) {
x <- matrix(1:n, nrow=n, ncol=n)
abs(x-col(x))+1
}
> symmat(4)
[,1] [,2] [,3] [,4]
[1,] 1 2 3 4
[2,] 2 1 2 3
[3,] 3 2 1 2
[4,] 4 3 2 1
----------------------------------------------
David L Carlson
Associate Professor of Anthropology
Texas A&M University
College Station, TX 77843-4352
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Erin Hodgess
> Sent: Thursday, September 06, 2012 8:11 PM
> To: R help
> Subject: [R] creating a symmetric matrix
>
> Dear R People:
>
> Suppose I have the following:
>
> x <- 1:4
>
> And I want to create the following matrix:
>
> 1 2 3 4
> 2 1 2 3
> 3 2 1 2
> 4 3 2 1
>
> Is there a function in place for this, please? I looked at symMatrix
> in micEcon and some of the items in Matrix, but they didn't quite do
> it.
>
> I can put together something quickly, of course, but it seems likely
> that this would exist.
>
> Thanks,
> Erin
>
>
> --
> Erin Hodgess
> Associate Professor
> Department of Computer and Mathematical Sciences
> University of Houston - Downtown
> mailto: erinm.hodgess at gmail.com
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.